refac(mod_random): mv procedure defs to submodule

Author: rouson

src/mod_random.f90

@@ -10,30 +10,22 @@ module mod_random
   private
   public :: randn
 
-  real(rk), parameter :: pi = 4 * atan(1._rk)
-
   interface randn
-    module procedure :: randn1d, randn2d
-  end interface randn
 
-contains
-
-  function randn1d(n) result(r)
-    !! Generates n random numbers with a normal distribution.
-    integer(ik), intent(in) :: n
-    real(rk) :: r(n), r2(n)
-    call random_number(r)
-    call random_number(r2)
-    r = sqrt(-2 * log(r)) * cos(2 * pi * r2)
-  end function randn1d
-
-  function randn2d(m, n) result(r)
-    !! Generates m x n random numbers with a normal distribution.
-    integer(ik), intent(in) :: m, n
-    real(rk) :: r(m, n), r2(m, n)
-    call random_number(r)
-    call random_number(r2)
-    r = sqrt(-2 * log(r)) * cos(2 * pi * r2)
-  end function randn2d
+    module function randn1d(n) result(r)
+      !! Generates n random numbers with a normal distribution.
+      implicit none
+      integer(ik), intent(in) :: n
+      real(rk) :: r(n)
+    end function randn1d
+
+    module function randn2d(m, n) result(r)
+      !! Generates m x n random numbers with a normal distribution.
+      implicit none
+      integer(ik), intent(in) :: m, n
+      real(rk) :: r(m, n)
+    end function randn2d
+
+  end interface randn
 
 end module mod_random

src/mod_random_submodule.f90

@@ -0,0 +1,24 @@
+submodule(mod_random) mod_random_submodule
+  implicit none
+
+  real(rk), parameter :: pi = 4 * atan(1._rk)
+
+contains
+
+  module function randn1d(n) result(r)
+    integer(ik), intent(in) :: n
+    real(rk) :: r(n), r2(n)
+    call random_number(r)
+    call random_number(r2)
+    r = sqrt(-2 * log(r)) * cos(2 * pi * r2)
+  end function randn1d
+
+  module function randn2d(m, n) result(r)
+    integer(ik), intent(in) :: m, n
+    real(rk) :: r(m, n), r2(m, n)
+    call random_number(r)
+    call random_number(r2)
+    r = sqrt(-2 * log(r)) * cos(2 * pi * r2)
+  end function randn2d
+
+end submodule mod_random_submodule